Determination of the elastoplastic properties of Ti-6Al-4V alloy manufactured by electron beam melting
ISSN: 1355-2546
Article publication date: 24 August 2023
Issue publication date: 27 November 2023
Abstract
Purpose
This study aims to evaluate and assess the elastoplastic properties of Ti-6Al-4V alloy manufactured by Arcam Q20 Plus electron beam melting (EBM) machine by a tensile test campaign and micro computerized tomography (microCT) imaging.
Design/methodology/approach
ASTM E8 tensile test specimens are designed and manufactured by EBM at an Arcam Q20 Plus machine. Surface quality is improved by machining to discard the effect of surface roughness. After surface machining, hot isostatic pressing (HIP) post-treatment is applied to half of the specimens to remove unsolicited internal defects. ASTM E8 tensile test campaign is carried out simultaneously with digital image correlation to acquire strain data for each sample. Finally, build direction and HIP post-treatment dependencies of elastoplastic properties are analyzed by F-test and t-test statistical analyses methods.
Findings
Modulus of elasticity presents isotropic behavior for each build direction according to F-test and t-test analysis. Yield and ultimate strengths vary according to build direction and post-treatment. Stiffness and strength properties are superior to conventional Ti-6Al-4V material; however, ductility turns out to be poor for aerospace structures compared to conventional Ti-6Al-4V alloy. In addition, micro CT images show that support structure leads to dense internal defects and pores at applied surfaces. However, HIP post-treatment diminishes those internal defects and pores thoroughly.
Originality/value
As a novel scientific contribution, this study investigates the effects of three orthogonal build directions on elastoplastic properties, while many studies focus on only two-build directions. Evaluation of Poisson’s ratio is the other originality of this study. Furthermore, another finding through micro CT imaging is that temporary support structures result in intense defects closer to applied surfaces; hence high-stress regions of structures should be avoided to use support structures.
Keywords
Acknowledgements
This study is a part of a joint project between Turkish Aerospace Industries, Inc., and Middle East Technical University, Department of Aerospace Engineering (Project Code: DDEKL1, Number: 2019–03-13–32-00–03), which is supported by the Turkish Presidency of Defence Industries (SSB).
Citation
Yılmaz, F., Gürses, E. and Şahin, M. (2023), "Determination of the elastoplastic properties of Ti-6Al-4V alloy manufactured by electron beam melting", Rapid Prototyping Journal, Vol. 29 No. 10, pp. 2149-2163. https://doi.org/10.1108/RPJ-02-2022-0041
Publisher
:Emerald Publishing Limited
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